Effects of 1-methylcyclopropene treatment on fruit quality and antioxidant activities of ruby-S apples during cold storage

The effects of 1-methylcyclopropene (1-MCP) on the fruit quality and antioxidant activity of ruby-S apples were evaluated during cold storage. The fruits were treated with 0 (control) and 1 μL/L 1-MCP and stored at 0℃ for six months. The assessments were performed at 0 (harvest), 3, and 6 months of storage. Compared with the control, the 1-MCP-treated fruits exhibited a reduced internal ethylene concentration and slowed appearance of greasiness on the fruit skin. In addition, 1-MCP treatment helped maintain a reduction in flesh firmness, titratable acidity, and peel color attributes (L* and b*) of the fruit. However, 1-MCP treatment did not affect fruit weight loss, soluble solids content, or peel color a* value. The 1-MCP treatment helped delay the reduction in total phenolics (TPC) and total flavonoids (TFC) content as well as total antioxidant determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (RSA) in the peel tissue. In the pulp tissue, 1-MCP affected only TPC, and not TFC or DPPH RSA. Overall, this study suggests that 1-MCP treatment helps maintain the desirable fruit quality attributes of ruby-S apples during ripening, but its effect on antioxidant activity depends on the tissue type (peel and pulp) of the fruit.